This adds DDR training. The training has a small chance of failing,
and then the training is restarted.
DDR training cannot be done meaningfully while the software is
in DDR. If the system is intended to run from eNVM, like a
bootloader, the linker script should be tuned to utilize the envm
region as follows:
envm (rx) : ORIGIN = 0x20220100, LENGTH = 128K - 256
l2lim (rwx) : ORIGIN = 0x08000000, LENGTH = 1024k
256 bytes are reserved for the system; The fixed block may be
installed from the 'hart-software-services' -repository:
https://github.com/polarfire-soc/hart-software-services.git
For example, the 256-byte image: hss-envm-wrapper-bm1-dummySbic.bin
may be prepended on the nuttx bootloader image in the following
manner:
cat hss-envm-wrapper-bm1-dummySbic.bin > nuttx_bootloader.bin
cat nuttx.bin >> nuttx_bootloader.bin
riscv64-unknown-elf-objcopy -I binary -O ihex --change-section-lma
*+0x20220000 nuttx_bootloader.bin flashable_image.hex
This provides an image 'flashable_image.hex' that may be flashed on
the eNVM region via Microsemi Libero tool.
Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
Add a driver for CorePWM block, which can be instantiated on PolarFire SOC FPGA
This supports 2 CorePWM blocks on the FPGA. One CorePWM block provides 8 PWM output signals
